Underclocking FX-9370 for Safety?

[TheEschaton]

I have a sweetheart deal potentially lined up to get an FX-9370, which for reference to those who don't want to have to look this up and don't already know, is one of AMD's more questionable choices in recent memory - a 4.4ghz Piledriver octocore CPU with a truly insane 220W TDP. Only certain 990FX boards were rated to run it, even though it will boot on most other AM3+ boards... and that is where my quandary comes in.

See, I have only an 760G chipset mobo capable of supporting it. This board is rated by Gigabyte to support CPUs up to 140W TDP (indeed, I have a 140W Phenom II X4 965 that will be going into it otherwise). It has a 4+1 phase design.

So here's my question - can I underclock and undervolt the FX-9370 to the point where its TDP is something more like 140W without disabling more than 2 cores, and what kind of performance could I expect out of it in such a situation? Do I need to expect anything special from my PSU under such circumstances? I have heard that the FX-9370 is essentially just a highly binned, factory OC'd FX-8320, which has a perfectly acceptable 125W TDP, so if I reduce the part down to somewhere between 3.5-4.0ghz, I should be good to go, right?

 

[drescherjm]

can I underclock and undervolt the FX-9370 to the point where its TDP is something more like 140W without disabling more than 2 cores,

Yes. Remember the 95W 8 core is the same exact silicon as the 220W 8 core. The difference in TDP is mainly the voltage then the frequency that each run at.

I have heard that the FX-9370 is essentially just a highly binned, factory OC'd FX-8320, which has a perfectly acceptable 125W TDP, so if I reduce the part down to somewhere between 3.5-4.0ghz, I should be good to go, right?

I say yes.

 

[TheEschaton]

Yes. Remember the 95W 8 core is the same exact silicon as the 220W 8 core. The difference in TDP is mainly the voltage then the frequency that each run at.

I guess then the big question is what do you estimate the best resulting frequency would be with a TDP of around 140W?

 

[drescherjm]

I think you will be fine around 4 GHz. Try to back the voltage off until you get instability then increase it to give you a little margin.

 

[TheEschaton]

I think you will be fine around 4 GHz. Try to back the voltage off until you get instability then increase it to give you a little margin.

That was exactly my thinking, but I just wanted to be sure. Thanks for the confirmation.

If anyone else has thoughts to the contrary, I will be listening here. I don't actually get the CPU until sometime this weekend, so there's some time to mull this over.

 

[ManofGod]

*BOOM* Goes the vrm section. If you can, just pick up a MSI 970 Gaming board, you would be much better off. (Only $99 and works great.)

 

[TheEschaton]

*BOOM* Goes the vrm section. If you can, just pick up a MSI 970 Gaming board, you would be much better off. (Only $99 and works great.)

Yeah, it's possible. I spent about $18 for that board shipped, though, and I will have spent almost nothing getting the FX-9370, so if there's a decent chance that this won't happen, then I'd like to try it (for SCIENCE). But if you're saying that no matter what I do it's definitely gonna blow out my VRMs, then I just won't do it (I'll sell the FX chip separately and make a small profit). No point in spending money on this; I already have a CPU that offers comparable gaming performance in some ways running fine and I'd rather not spend $90 on whatever upgrade this chip might represent from that.

 

[ManofGod]

Yeah, it's possible. I spent about $18 for that board shipped, though, and I will have spent almost nothing getting the FX-9370, so if there's a decent chance that this won't happen, then I'd like to try it (for SCIENCE). But if you're saying that no matter what I do it's definitely gonna blow out my VRMs, then I just won't do it (I'll sell the FX chip separately and make a small profit). No point in spending money on this; I already have a CPU that offers comparable gaming performance in some ways running fine and I'd rather not spend $90 on whatever upgrade this chip might represent from that.

Dang, wish I could get a FX9370 for next to nothing. If you sell it, the most I would be willing to pay is $100. (Not joking, just figuring a used 9370 is not going to go for anywhere near what a new one could.)

 

[dragonstongue]

Generally Intel, AMD, Nvidia and many others do batch testing, not fine tuning so while the cpu may run at X voltage for Y speed does not mean it will not run at same speed with less voltage, and def run slower, less power. If you do the tuning in BIOS before full boot you should be ok.

For example, my 955 default wants to run and will 1.38-1.41v for 3.2Ghz, I can make it run that 3.2 at 1.32v 3.0Ghz at 1.28v 1.41 lets me hit 3.9 almost 4.0Ghz.

Depends on how "good" your particular chip is for how much it can be downvolted for same frequency or simply downvolted/clocked. Processors are like snowflakes, the look similar but all are slightly different

 

[TheEschaton]

Dang, wish I could get a FX9370 for next to nothing. If you sell it, the most I would be willing to pay is $100. (Not joking, just figuring a used 9370 is not going to go for anywhere near what a new one could.)

Yeah craigslist is a wonderful place. I've told the guy he's getting a bad deal but he seems more interested in just being a cool dude than anything else. If the trade doesn't turn out to be contingent on something like me showing him my end results with his old CPU, then I will certainly be in touch with you re: that price

 

[kirbyrj]

If you're not buying a new board, sell the cpu and buy one that won't blow up your current board. Personally, I'd make a thread in FS/FT that says something like, trade your 8320e+$50 for my 9370.